Acoustic Vs. Elastic 3-D Full-Waveform Inversion at the East Pacific Rise 9º50'n'
M. Marjanovic, R.E. Plessix, A. Stopin and S. Singh
Event name: 80th EAGE Conference and Exhibition 2018
Session: FWI - Case Histories
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 5.48Mb )
Price: € 20
Over the last decade the acoustic 3-D full-waveform inversion technique has become almost a common tool for imaging geologically complex structures in marine, as well as in land settings. However, it has been speculated that excluding the elastic effect from the waveform modeling in some cases could have a big impact and potentially result in an erroneous image of the subsurface. To examine the contribution of the elastic effect, we conduct acoustic and elastic 3-D FWI on the 3-D seismic data, collected at the East Pacific Rise (EPR) 9º50’N, deep-water environment (minimum depth ~2500 m) with high compression velocity contrast at the seafloor. We first establish a strategy for inversion within the EPR setting, which suggest simultaneous multi-parameter inversion for the frequencies <7 Hz. Comparison of the results shows that the total misfit for the elastic case is reduced for ~10% more when compared to the acoustic, suggesting that the elastic effect is not negligible. Furthermore, the images of the upper-crust obtained using the two approaches differ significantly, not only in velocity amplitude, but also structurally, leading to different implications for crustal accretion processes, with the elastic approach leading to geologically more plausible solution.